Another Sway Bar compilation, reconciling the data

[GTP]

In addition to 305’s in the front, your PP2 doesn’t under steer because Ford increased the rear PP2 bar by 67% over the PP1 bar ( and the front bar by only 12%)
your Steeda bar setup added 200 lbs/in in the front bar (a 78% increase over the PP1 bar and a 60% increase over the PP2 front bar) and slightly lowered the stiffness in the rear compared to the PP2 bar. Rear happy oversteer is exactly what you dialed in.

@Bossdog are you sure you don't have this backwards? If he stiffened his front bar a lot more than his rear, his car would understeer more.

you can calculate that from the spreadsheet in the first post
Steeda second stiffest hole, 525 lbs/in divided by softest hole in the rear, 189 lbs/in equals a front rear ratio of 1.3 : 1 Any thing lower that the PP2 bar ratio of 1.6 : 1 will have more oversteer ( loose rear) compared to your original PP2 set

But this part of your post seems consistent with how sway bars work. (But inconsistent with what you wrote in the first half of your post.)

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[Bossdog]

@Bossdog are you sure you don't have this backwards? If he stiffened his front bar a lot more than his rear, his car would understeer more.



But this part of your post seems consistent with how sway bars work. (But inconsistent with what you wrote in the first half of your post.)

You’re correct, I’ll pull this post and review

 

[GTP]

You’re correct, I’ll pull this post and review

Yeah, thanks. It was tricky to word my response to properly convey meaning.

I think it is easy to misunderstand how bars work and (wrongly) assume a stiffer bar means more traction at that end. I find myself double-thinking this often. One way I keep myself straight is to imagine an infinitely stiff bar. The bar would make the outside wheel feel double the spring rate due to the full assist of the inside spring. You can even see this in photos of a cornering car with the inside front wheel lifted off the track. The car essentially "tips" and corners on 3 wheels and the inside front tire has NO traction. Hence understeer. (Bossdog, I know you know all this.)

 

[webspoke]

When I was tuning my setup, I wanted real data to compare 2 different bars and their hole settings. This works for the rear bar as it will deflect a meaningful amount with a modes weight (40-50lbs).

Basically strapped a fixed weight to each hole and measured the deflection. This let me change to a bar with enough adjustment range to cover my softest desired settings.

Main tuning was T3 at my local Eagles Canyon Raceway. Double apex, 50-60mph. No aero effects, and the double apex required good turn in, stable mid at steady throttle, but also needed the car to tuck the nose in on exit with a lift or throttle so as not to run wide.

My experieance, the steeda comp bar was too soft. OEM bar was decent, 25mm bar (bmr here) adjustment range went from soft to too much. Middle hole was very usable. Steeda comp was a stable setup but with too much push on exit, that took a large dose of throttle to neutralize. Sounds fun, but the rear slides and front push heat up the tire too much and they start going off quicker than just normal heat soak. So optimum time trial laps are very limited.

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